The present invention relates to the support of refractory to protect surfaces from high temperature, corrosive slag which forms complex sulfates, and corrosive acids formed below the dew point of gases. More particularly, the invention relates to the process of forming a supporting framework of strands or fibers of structural material which can be attached to a surface which will effectively hold refractory introduced into interspaces of the framework.
In heat exchange equipment exposed to direct and indirect sources of heat, the temperatures and environment may often require the protection of the surfaces of the equipment by a layer of refractory or other ceramics. The manner in which the refractory is attached to the equipment surface has always been a problem. Because of the different thermal expansion rates between the equipment (metal) and the refractory, and the corrosive nature of the environment, the refractory eventually falls off the surface, or quickly wears out. Another problem is securely attaching or fixing refractory onto surfaces that are not flat or planer, such as rounded or other irregular shapes. My previous patent application U.S. Ser. No. 446,734, filed on Dec. 3, 1982, entitled "A Process For Bonding Refractory To Surfaces", overcomes some of the above problems. That application discloses a process for bonding refractory to a flat surface by first applying a viscous liquid-like vehicle as a coating to strands or fibers of metal, to hold finely-divided brazing material on the surfaces of the strands. A mat of the coated strands or fibers is next spread in a layer over the flat surface or substrate to be protected, and brought to the brazing temperature to form the desired bond. At the brazing temperature forming the bond, the viscous vehicle is evaporated, leaving no residue which deteriorates the quality of the brazing bond of the strands or fibers to each other, and the brazing bonds between the strands or fibers and the substrate.